A phospholipid is "an ester of glycerol with two fatty acids and phosphoric acid (H3PO4) or a derivative of phosphoric acid group (like H2PO4CH2CH2N(CH3)3).
Phospholipids have a hydrophilic head (the phosphate group) and a lipophilic tail (the fatty acids)."
There are 2 main types of lipids: phosphoglycerides or glycerophospholipids
molecule: phosphate
What is a phospholipid?
http://antoine.frostburg.edu/cgi-bin/senese/searchglossary.cgi?query=phospholipids&shtml=%2Fchem%2Fsenese%2F101%2Fglossary.shtml